Infection & inflammation Flashcards
What is infective endocarditis?
An infection involving the endocardium including the valvular structures, the chordae tendineae, sites of septal defects, or the mural endocardium.
How does infective endocarditis occur?
Non-bacterial thrombotic endocarditis (sterile platelet vegetation due to Venturi effect) acts as pre-requisite for adhesion and invasion → bacterial infection (usually via skin) penetrates endocardium of heart → intracardiac effects (valvular insufficiency) & systemic effects
What are the causes of endocarditis?
Staph Aureus (IVDU) Strep Viridans (Dental) Staph Epidermis (Prosthesis) Pseudomonas HACEK organisms
What are the risk factors for endocarditis?
Valvular disease Rheumatic fever/valve disease Structural congenital issues (ASD, VSD, PDA) Hypertrophic cardiomyopathy IVDU
What are the Sx of acute infective endocarditis?
Fever + new murmur = ENDOCARDITIS UNTIL PROVEN OTHERWISE
Fever >38/chills/rigors
HF- dyspnoea, crackles
How does sub-acute infective endocarditis present?
Fever >38, chills, rigors
Weight loss
Fatigue
Flu-like Sx
What are the signs of infective endocarditis?
- Osler’s nodes: Painful pulp of finger
- Roth spots: Retinal haemorrhages with pale centre
- Janeway lesions: Irregular, painless, erythematous macule on hypo/thenar eminence
- Splinter/Subungal haemorrhages
- Petechiae: Conjunctiva, hands/feet, chest/abdo, oral mucosa
- Clubbing
What murmur is heard in infective endocarditis?
AORTIC REGURG- Diastolic murmur & collapsing pulse
What criteria is used to diagnose infective endocarditis?
Duke’s criteria:
- 2major
- 1major + 3minor
- 5minor
What are the investigations for infective endocarditis?
-3 serial blood cultures in 24hours
-TTE/TOE
Bloods: FBC, Film, CRP, ESR, LFTs
Urinalysis
ECG
CXR
How is infective endocarditis managed?
BUFALO if Septic
IV Abx: 4-6w Empirical =
NORMAL: Amox +/- Gent or Vanc + Gent
PROSTHETIC: Vans + Rifamp + Gent
What are the antibiotics used against specific organisms causing infective endocarditis:?
Staph = Fluclox >4w
Staph (prosthesis) = Fluclox + Rifamp + Gent for 6w
Strep = BenPen 4-6w
Enterococci/HACEK = Amox + Gent
What are the complications of infective endocarditis??
CVA: Stroke/TIA
Congestive cardiac failure
What are the major and minor components in Duke’s criteria?
MAJOR:
- Positive blood culture in 2 separate cultures
-Evidence of IE: mass on valve, abscess, new valvular regurg
MINOR:
- Predisposing heart condition
-IVDU
-Fever >38
-Vascular phenomenon: Janeway nodes, etc
- +ve blood culture not meeting major criteria
-Immunological: Osler nodes, RF, roth spots, GN
What is rheumatic fever?
Develops 2-6w following immunological reaction to recent Strep Pyogenes infection
How is rheumatic fever diagnosed?
2 major criteria
1 major criteria + 2 minor
Evidence of recent strep infection
What are the major & minor criteria for rheumatic fever?
MAJOR: Erythema marginatum, Sydenham’s chorea, Polyarthritis, Carditis (endo-, myo- or peri-), Subcut nodules
MINOR: ↑ESR/CRP, Pyrexia, Arthralgia, Prolonged PR
What is pericarditis?
Inflammation of the pericardial sac
How does pericarditis cause problems?
Volume of pericardial fluid ↑ in serous pericardium or thickens (pericardial effusion)
Pressure on heart
DIASTOLIC HF → ↓SV ↓CO
What is chronic pericarditis?
> 6m
↑fibroblasts = ↑fibrin resulting thick and stiff pericardium → pressure on heart → ↓SV → ↑HR)
What are the causes of pericarditis?
Idiopathic Viral: Coxsackie B Dressler Syndrome Uraemic Autoimmune diseases (RA, SLE) Cancer + RT
How does pericarditis present?
Fever
Central chest pain: Pleuritic, worse when supine, relieved by leaning forwards, radiates to neck
Dyspnoea
Pericardial rub, ↓heart sounds
How is pericarditis investigated?
ECG: QRS changes
Stage1) Saddle ST elevation, PR depression
Stage2) ST normal, flattened T waves
Stage3) T waves invert
Stage4) Normal ECG
CXR: Pericardial effusion- Water bottle sign
ECHO:
Acute= heart looks like it’s ‘dancing’ in pericardial sac
Chronic = heart stiff & constricted
How is pericarditis treated?
Rest
Tx cause: Dialysis = uraemia
Analgesia: NSAIDs- Naproxen
What medication should be stopped in pericarditis?
Corticosteroids- worsen oedema/effusion
Phenytoin
What are the complications of pericarditis?
Conversion to chronic
Tamponade
Effusion
Constrictive
What is pericardial effusion?
Increased accumulation of fluid in serous pericardium
50ml → 2 L
What are the types of fluid in pericardial effusion?
Transudative
Exudative
Blood
How can pericardial effusions be grouped?
LARGE: Associated w/malignancy, TB, uraemic, myxoedema
LOCULATED: Common w/scarring- post-op/trauma
What are risk factors for pericardial effusion?
Idiopathic Infectious: Viral, TB, HIV, Syphilis, Bacterial MI AKI/CKD: Uraemic Malignancy Hypothyroidism
What are the Sx of pericardial effusion?
Chest pain/pressure/discomfort- worse when supine, better sitting forward Cough/dyspnoea Hoarseness Dizzy & syncope Palpitations Anxiety Confusion Pericardial rub Ewart's sign: Large effusion compressing LLL causing bronchial breathing
How is a pericardial effusion investigated?
CXR: Water bottle sign
ECG: Low voltage QRS complexes
ECHO: ECHO-free zone
How is pericardial effusion managed?
Supportive
Tx cause
Pericardiocentesis
What are the complications of pericardial effusion?
Cardiac tamponade
What is lymphoedema?
Progressive swelling of a body part (usually limb) following disruption of the lymphatic system
Results in lymph accumulating in interstitial space
What are the common causes of lymphoedema?
80% affected before lymphoedema occurs
- Lymphatic hypoplasia
- Obstruction
- Fibrosis
- Malignancy & Cancer Tx (LN dissection, RT, neoplastic infiltration)
- Nematode infection
- Trauma (penetrating)
How are lymphoedema causes categorised?
PRIMARY: Rare, idiopathic & usually sporadic
SECONDARY: Occurs post-injury or Tx
How does lymphoedema present?
Hx of trauma/malignancy
Limb heaviness/weakness
Non-pitting oedema
Skin changes: Hyperkeratosis, papillomatosis, induration, exudative (lymph fluid)
How is lymphoedema investigated?
Lymphoscintigram: Inject isotope into area, wait 45m-2hr then image shows areas of no uptake
How is lymphoedema managed?
1) Skin care: Moisturise, bathing, protective clothing AND Compression bandaging AND Elevation AND Exercise & weight control 2) Manual drainage
